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Good specs and regular maintenance can defend your equipment against the corrosive attack of de-icing chemicals.
Sodium chloride, calcium chloride, magnesium chloride! They go from bad to worse. Road salt—sodium chloride—long used in states affected by snow and ice during the winter months, was a known corrosion-inducing agent. In recent years, however, almost all state transportation departments have decided to replace or augment sodium chloride with other ice control chemicals—chemicals that are even more aggressive in inducing corrosion.
The downsides to the use of magnesium chloride and calcium chloride as de-icing agents are serious in terms of the potential increase in maintenance time and costs required to address corrosion. State and local agencies often apply these chemicals prior to any snowfall, increasing the likelihood and degree of exposure to trucks and trailers. These materials are especially destructive because of their ability to cling to the underbody of a vehicle and re-crystallize as they slowly dry out. By their very nature, they attract and absorb moisture from the surrounding environment, keeping them in a state of semi-solution for extended periods of time, which enhances their corrosiveness.
According to a study funded by the Federal Highway Administration, corrosion costs U.S. businesses an estimated $276 billion each year. It is estimated that the costs associated with corrosion caused by anti-icing chemicals have increased more than tenfold in recent years. A University of Idaho study indicated that the U.S. transportation industry spends more than $23 billion annually addressing the problem. For any company hauling freight, this equates to unacceptable costs for repairs attributed to corrosion and the potential for premature retirement of equipment.
Because of their long service life—as long as 20 years for some models—trailers are particularly vulnerable to attack by these chemicals. While trailer manufacturers and their supplier partners who furnish the vehicle’s electrical systems have made great strides in recent years in engineering products that protect against corrosive attack, fleet managers are wise to address the potential high costs associated with corrosion when spec’ing new trailers and designing maintenance programs for in-service vehicles.
Recognizing the growing number of problems associated with de-icing chemicals, trailer suppliers all have introduced product improvements to combat the threats. For example, Heil Trailers’ Bill Harris said, “For all of our product segments, magnesium chloride corrosion is a very important issue. Highway departments are using magnesium chloride on the roads for de-icing, and it can eat through frames, wiring, fittings, etc.” To address the problem, Heil is developing and using undercoatings and powder coating options.
The threat of corrosive damage from roadway de-icing chemicals is only one reason more fleets are considering bringing trailer maintenance under their direct control, according to Rod Erlich, chief technology officer at Wabash National. “More and more fleets are bringing trailer maintenance in-house because the maintenance programs can be better managed,” he said. “The larger the fleet, the more they tend to bring maintenance operations in-house.”
Erlich believes one of the biggest challenges facing trailer makers is developing technologies and components that eliminate or reduce trailer maintenance. “The undercarriage is driving the most change in this area,” he said. “We’re pursuing components and technologies that reduce or eliminate maintenance in the undercarriage for 10 or more years.” For example, all Wabash undercarriages are now hot-dipped galvanized.
And as trailer maintenance grows as an issue, it’s starting to outweigh price in the minds of many fleets, Erlich noted. “Maintenance and reduced operating costs are, of course, primary concerns for customers. As companies better understand their equipment maintenance costs, their emphasis shifts toward lifecycle value. As a result, a higher purchase price is becoming less important if maintenance costs are reduced and equipment uptime is increased. The total cost of ownership can be lower than equipment with a low initial purchase price.”
Great Dane is another trailer supplier that has addressed the growing problem caused by the use of corrosive road chemicals. It uses corrosion-resistant undercoating for steel underbody components of all its dry freight and reefer trailers. Also standard is the use of a two-step epoxy primer and urethane topcoat for dry freight rear frames and platform trailers.
Great Dane has also introduced a “Total Protection Package” that includes:
• CorroGuard, a sprayed-on thermoplastic coating for suspensions and support gear,
• Coated Accuride aluminum wheels designed to eliminate the need for polishing or cleaning with harsh abrasives,
• A Grote light system with LED lights sealed against moisture intrusion,
• Corrosion-resistant rear frames, and
• Swing doors on dry freight vans are made out of a composite material consisting of galvanized steel skins and a polymer core.
|Not your daddy’s undercoating
Just as new products have been developed to help control the dangers of ice on the roads, new products have also been introduced to protect vehicles from the corrosive effects of these new chemicals. Two representatives of Automotive International Inc., Rick Hallberg, president and CEO, and Dave Besuden, vice president of sales and marketing, joined forces to talk about what fleet managers can do to minimize damage from corrosion.
They pointed out that fleets too often identify undercoating with old-fashioned tar-based or rubberized products, both of which have poor adhesive characteristics. Many products on the market today are several generations beyond such formulations and offer excellent, long-term protection against corrosive road chemicals.
Cavity Wax is a liquefied petroleum product designed to fight corrosion in areas where moisture can accumulate, like a trailer’s suspension system. The product can be applied with spray equipment or brushed on. Hallberg said that the best time to apply a corrosion protective product is when the trailer is new, but it also can be applied later on, particularly when a trailer is being refurbished.
Besuden pointed out the importance of frequent washing with a carefully-selected soap. He said, “Some soaps on the market are not capable of removing magnesium chloride from the equipment. In such a case, the wash process can actually be driving magnesium chloride further under rivets and bolt heads, where rust can form. Fleets should select a wash product that is capable of removing magnesium chloride and calcium chloride residue and not just hiding it.” He said that Automotive International is introducing a product specifically designed to remove corrosive road chemicals.
Corrosion problems are particularly prevalent in the northern states, but can be found anywhere acid rain exists. Since corrosion can quickly form at spots where gravel, stones etc. have penetrated protective coatings, it is important to keep these barriers intact. Proper maintenance of equipment is crucial for optimum corrosion protection. Great Dane recommends two simple preventive maintenance steps that can help avoid major repairs of a trailer in the long run:
• Frequent pressure washing with a properly mixed ratio of fresh water and soap, especially in the undercarriage area, helps remove corrosive chemicals used for de-icing. Cleaning procedures should include a low to mild pressure application to ensure against lifting fresh/new coatings at abraided areas, as well as thorough rinsing.
• Repair any damaged areas of the coating as soon as possible to prevent spot corrosion that can spread.
The lighting systems of trailers can be particularly vulnerable to corrosive road chemicals if improperly designed or maintained. According to Grote engineers, during the summer months, the wiring is exposed to the heat and direct sun rays.
The winter season then puts the trailer wiring systems through the greatest salt attack known throughout history. Eleven times more salt is put on the highways during the short winter season than the total population of the U.S. puts on the table or uses for food preservation and preparation in a year. Corrosive chemicals will find their way into any unprotected wire end or improper splice. The result is corroded wire, which greatly increases resistance and local operating temperatures, all resulting in harness and lamp destruction. Salt creep does not recognize any boundaries other than total exclusion.
To address these concerns, Phillips Industries offers a number of maintenance tips for electrical systems:
• Specify premium sealed wiring systems whenever possible.
• Opt for sealed wiring connectors. Always use SAE J560 sockets on trailers.
• Always use dielectric grease when opening and resealing plugs and junction boxes.
• Never probe through insulation when checking for electrical continuity.
• Never splice into a wiring system, even with shrink tubing to reseal the splice.
The use of corrosive chemicals—those containing chlorine—is not going away any time soon. There are some alternatives being worked on, but don’t count on anything other than the current products being used for many years to come.
Even if your fleet does not include operations in the northern tier of states, your vehicles are exposed to corrosive chemicals in the form of acid rain. Protect your equipment with good specs and regular maintenance.
Proper repairs are critical
Addressing the problems that road chemicals can cause to trailer electrical systems, Brad Van Riper, vice president of engineering and chief technology officer at Truck-Lite, says that corrosion is still caused by the ingress of water into the system even though the systems are sealed when vehicles leave the factory. While corrosion problems can be caused by physical damage—for example, if a wire support is removed and ice buildup results in a loosed connection due to vibration—the most common cause is from an improper repair.
He said, “All too often, even in sophisticated maintenance operations, we see insulation displacement splices made that are not sealed. Such a practice will quickly cause the electrical system to be compromised because, much like a wick on a candle, corrosive chemicals on today’s roads will wick into the wire very quickly. They will cause the harness to deteriorate from the inside out because there’s no place for the water to go other than into the harness.”
Another frequent problem is caused by using an incorrect wire when making a repair involving a sealed connector. If the wire is not the same outside diameter as the original, the seal won’t work. Van Riper said, “I think it would be a good idea for every maintenance facility to have a gauge to help identify not only the conductor of the wire, but also the type of insulation on the wire. Wire jackets that are capable of withstanding greater abrasion and higher temperatures are only a few pennies more than a PVC insulated wire. Such gauges are available from tool jobbers, as well as from connector manufacturers.”
Harness manufacturers will be offering a training session on proper maintenance procedures for wiring systems at the upcoming meeting of the ATA Technology and Maintenance Council next February in Tampa, Fla. For more information, visit TMC.truckline.com. Training is also available on an ongoing basis from harness suppliers like Truck-Lite.